Abstract

Grain counting by eye is a tedious and time-consuming technique but one with great potential in cell kinetics and for the study of DNA excision repair activity (unscheduled DNA synthesis or UDS). We have been investigating the levels of UDS in human skin sections exposed in situ to ultraviolet radiation using a short-term incubation in tritiated thymidine and autoradiography and the decline in UDS levels with time (repair kinetics). We have adapted an automated image analysis system automatically to assess the number of grains over epidermal cell nuclei in autoradiographs of sections of epidermis. An excellent correlation was observed between visual counting and machine measurement of the area (in pixels) occupied by silver grains. The levels of UDS declined with time as lesions are progressively repaired. The half time (+/- standard deviation) for the reduction in UDS is 7.25 +/- 0.18 h. The grain counts can be significantly increased by increasing the autoradiographic exposure, by increasing the concentration of tritiated thymidine and by increasing the incubation time.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.